A5087110669- Physics of Superconductivity and Magnetism
- Advanced Chemical Physics Studies
- Magnetic and transport properties of perovskites and related materials
- Rare-earth and actinide compounds
- Superconductivity in MgB2 and Alloys
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- High-pressure geophysics and materials
- Fullerene Chemistry and Applications
- ZnO doping and properties
- Machine Learning in Materials Science
- Spectroscopy and Quantum Chemical Studies
- Analytic Number Theory Research
- Electronic and Structural Properties of Oxides
- Theoretical and Computational Physics
- Catalytic Processes in Materials Science
- Atomic and Molecular Physics
- Advanced Mathematical Identities
- Catalysis and Oxidation Reactions
- Inorganic Chemistry and Materials
- Magnetic Properties of Alloys
- Graphene research and applications
- Surface and Thin Film Phenomena
- Algebraic and Geometric Analysis
- Advanced Algebra and Geometry
Max Planck Institute for the Structure and Dynamics of Matter
2019-2023
Center for Free-Electron Laser Science
2023
Universität Hamburg
2023
Daresbury Laboratory
2007-2020
Humboldt-Universität zu Berlin
2015
Scuola Internazionale Superiore di Studi Avanzati
2002-2007
University of Würzburg
1995-2005
AREA Science Park
2002-2003
Istituto Nazionale per la Fisica della Materia
2002
An approach to the description of superconductors in thermal equilibrium is developed within a formally exact density functional framework. The theory formulated terms three ``densities:'' ordinary electron density, superconducting order parameter, and diagonal nuclear $N$-body matrix. parameter are determined by Kohn-Sham equations that resemble Bogoliubov--de Gennes equations. matrix follows from Schr\"odinger equation with an effective interaction. These coupled each other via...
Over the last few years, extraordinary advances in experimental and theoretical tools have allowed us to monitor control matter at short time atomic scales with a high degree of precision. An appealing challenging route toward engineering materials tailored properties is find ways design or selectively manipulate materials, especially quantum level. To this end, having state-of-the-art ab initio computer simulation tool that enables reliable accurate light-induced changes physical chemical...
The density functional theory for superconductors developed in the preceding article is applied to calculation of superconducting properties several elemental metals. In particular, we present results transition temperature, gap at zero and thermodynamic like specific heat. We obtain an unprecedented agreement with experimental results. Superconductors both strong weak electron-phonon coupling are equally well described. This demonstrates that, as far conventional superconductivity...
Extreme pressure strongly affects the superconducting properties of "simple" elemental metals, such as Li, K, and Al. Pressure induces superconductivity in Li (as high 17 K) while suppressing it We report first-principles investigations dense Al based on a recently proposed, parameter-free, method. Our results show an unprecedented agreement with experiments, assess predictive power method over wide range densities electron-phonon couplings, provide predictions for where no experiments exist...
Abstract With big-data driven materials research, the new paradigm of science, sharing and wide accessibility data are becoming crucial aspects. Obviously, a prerequisite for exchange analytics is standardization, which means using consistent unique conventions for, e.g., units, zero base lines, file formats. There two main strategies to achieve this goal. One accepts heterogeneous nature community, comprises scientists from physics, chemistry, bio-physics, by complying with diverse...
Solid MgB$_2$ has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first non-trivial application of novel density-functional-type theory for superconductors, recently proposed by authors. Without invoking any adjustable parameters, obtain temperature, gaps, specific heat in good agreement with experiment. Moreover, our calculations show how Coulomb interaction acts differently s p...
An ab initio study of magnetic exchange interactions in antiferromagnetic and strongly correlated 3d transition metal monoxides is presented. Their electronic structure calculated using the local self-interaction correction approach, implemented within Korringa-Kohn-Rostoker band method, which based on multiple scattering theory. The Heisenberg constants are evaluated with force theorem. Based these corresponding Neel temperatures T_N spin wave dispersions calculated. obtained mean field...
We propose a simplified version of self-interaction corrected local spin-density (SIC-LSD) approximation, based on multiple scattering theory, which implements correction locally, within the KKR method. The aspect this new SIC-LSD method allows for description crystal potentials vary from site to in random fashion and calculation physical quantities averaged over ensembles such using coherent potential approximation. This facilitates applications SIC alloys pseudoalloys could describe...
The structural phase transitions and the fundamental band gaps of ${\text{Mg}}_{x}{\text{Zn}}_{1\ensuremath{-}x}\text{O}$ alloys are investigated by detailed first-principles calculations in entire range Mg concentrations $x$, applying a multiple-scattering theoretical approach (Korringa-Kohn-Rostoker method). Disordered treated within coherent-potential approximation. for various crystal phases have given rise to diagram good agreement with experiments other approaches. transition from...
First-principles electronic structure calculations are very widely used thanks to the many successful software packages available. Their traditional coding paradigm is monolithic, i.e., regardless of how modular its internal may be, code built independently from others, compiler up, with exception linear-algebra and message-passing libraries. This model has been quite for decades. The rapid progress in methodology, however, resulted an ever increasing complexity those programs, which implies...
The theory of ab initio semi-relativistic angle-resolved photoemission calculations is formulated within the real-space multiple-scattering and single-particle approximation. It has flexibility simplicity required for studying systems with layered structures more general complex geometries. For layer-resolved potentials are obtained self-consistently using Korringa-Kohn-Rostoker (KKR) method. advantage present approach that self-consistent potential photocurrent treated on same footing...
We apply to transition metal monoxides the self-interaction corrected (SIC) local spin density approximation, implemented locally in multiple scattering theory within Korringa–Kohn–Rostoker (KKR) band structure method. The calculated electronic and particular magnetic moments energy gaps are discussed reference earlier SIC results obtained linear muffin-tin orbital atomic sphere approximation method, involving transformations between Bloch Wannier representations, order solve eigenvalue...
This review tries to establish what is the current understanding of rare-earth monopnictides and monochalcogenides from first principles. The rock salt structure assumed for all compounds in calculations wherever possible electronic structure/properties these compounds, as obtained different ab initio methods, are compared their relation experimental evidence discussed. established findings summarised a set conclusions provide outlook future study design new materials.
We report first principles calculations of the superconducting properties fcc potassium under high pressure. Using a completely ab initio method we predict phase transition at $18\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. A maximum critical temperature about $2\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ is observed around $23\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, pressure which crossover between and KIII structure experimentally occurs. At higher pressure, when unstable, find, in phononically...
We describe an ab initio theory of finite temperature magnetism in strongly-correlated electron systems. The formalism is based on spin density functional theory, with a self-interaction corrected local approximation (SIC-LSDA). correction implemented locally, within the Kohn–Korringa–Rostoker (KKR) multiple-scattering method. Thermally induced magnetic fluctuations are treated using mean-field 'disordered moment' (DLM) approach and at no stage there fitting to effective Heisenberg model....
We explain a profound complexity of magnetic interactions some technologically relevant gadolinium intermetallics using an ab initio electronic structure theory which includes disordered local moments and strong f-electron correlations. The correctly finds GdZn GdCd to be simple ferromagnets predicts remarkably large increase Curie temperature with pressure +1.5 K kbar(-1) for confirmed by our experimental measurements +1.6 kbar(-1). Moreover, we find the origin...
A universal LDA-type density functional describing the electronic correlations in superconductors is developed from first principles. The constructed exchange-correlation free-energy density, ${f}_{\mathrm{xc}}^{\mathrm{hom}}$, of a homogeneous electron gas exposed to an external translationally invariant pairing field. quantity which function and induced order parameter, calculated by many-body perturbation theory.
We prove a spontaneous magnetization of the oxygen-terminated ZnO (0001) surface by utilizing multicode, SIESTA and KKR, first-principles approach, involving both LSDA+$U$ self-interaction corrections to treat electron correlation effects. Critical temperatures are estimated from Monte Carlo simulations, showing that at above 300 K is thermodynamically stable ferromagnetic. The observed half-metallicity long-range magnetic order originate presence $p$ holes in valence band oxide. mechanism...
Using first-principles calculations we have studied the valence and structural transitions of rare earth monotellurides RTe (R = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm Yb) under pressure. The self-interaction corrected local spin-density approximation is used to establish ground state configuration as a function volume for in both NaCl (B1) CsCl (B2) structures. We find that ambient conditions all are stabilized B1 structure. A trivalent (R3+) predicted majority RTe, with exception...
The nature of the weakly dispersive electronic band near Fermi level observed in photoemission experiments on diluted magnetic semiconductor GaMnAs is investigated theoretically. combination experimental features appears puzzling. We show that formation closely related to presence Mn interstitial impurities. states forming have predominantly minority-spin Mn-3d character. low intensity explained by content are robust with respect calculational technique [local density approximation (LDA), LDA + U].